Definite diagnosis of specific pathological processes that lead to dementia requires a thorough neuropathological examination of the brain. Alzheimer's disease (AD), the predominant cause of dementia, is a heterogeneous clinico-pathological entity with large variation in neuropathologic changes, reflecting multiple etiological factors. Therefore detailed pathological characterization as well as careful preservation of post-mortem brain tissues are of vital importance for our understanding of this complex disease. To meet these goals, the main function of the Neuropathology Core is to provide accurate neuropathologic diagnoses and clinico-pathological correlations, to maintain and expand the ADC brain and tissue bank as a resource for investigators studying AD, and to participate in collaborative projects involving the use of brain bank material and neuropathological technologies. Uniquely, our Core has developed a strong base for investigation on (i) the contribution of vascular factors in dementia with an emphasis on imagingneuropathological correlations, and (ii) the heterogeneity of AD neuropathologies in an ethnically diverse population. Specifically, we will continue to 1) perform timely autopsies on the participants of the ADC longitudinal cohort and cognitively and neurologically normal controls;2) issue a standardized report on each case following consensus diagnostic criteria;3) follow a standardized protocol to obtain rapidly frozen and optimally preserved brain tissue for various research purposes;4) provide an in-depth neuropathological evaluation of cerebrovascular lesions following our established ischemic vascular dementia protocols;5) interact with other ADC Cores in the mission to expand our understanding of age-related neurodegenerative disorders and provide education to medical staff, researchers, students, and general public;and 6) collaborate with investigators locally and nationally to assist with design and techniques for experiments using tissue from our brain bank. We anticipate that our effort will provide invaluable service to AD patients, their families and to researchers studying AD. In addition, our effort will make unique contributions to our understanding of the "mixed pathologies" that are frequently encountered in AD patients.